Method of and explosive member for the blasting of blast-holes



H. G. ULRIK 1,816,100v

METHOD OF AND EXPLOSVE NBER FOR THE .BLASTING O F BLAST HOLES July 2s',1931.

Filed Aug. 15. 1929' IIIIIII @um iiiii i w iiiiii lllllllllll' .Ill'll`/1 Hop/rey Patented July 28, 1931 UNITED STA 'rlazs PATENT orf-'ICEIHANS GEORG ULBIK, F B'USTENARI, RUMANIA :mamon or' AND ExrLosIvE-ImnxnFon- THE BLAsTINe 'oF BLAST-HOLES f Application led August 15,` 1929.Serial No. 386,069.

` Heretofore foi; torpedoing blast-holes, thus .for blasting open hollowspaces, in .rocky ground| as well as also in soft ground veryf strongexplosive charges were usedy which 'l were enclosed in a thin-walledcasing of sheet metal or even of cardboard only. The wall oftheexplosive casing has been very thin and proportioned in view ofprotecting the char e against moisture only. The explosive memi orpercussion fuses were placed into the blastholes of a diameter adaptedtothe diameter of the explosive members in such -a manner, that theexplosive member contacted as much as possible with the surrounding wallof the blast-hole. y 5 However when workingin hard rocks, the explosionof the explosive members con'- structed in this way resulted in quiteother effects than in sand or other'soft ground.- In the first eventclefts were formed in the rock owin to the sudden shocks, so thatchannels or the passage of the oil to the blasthole were formed.Therefore explosions in rocky ground yielded a favourable result ifthin-walled explosive members are used. However in soft ground, forinstance sand, explosions carried out with explosive mem- Y bers,provided with thin-walled casings 80 containing thecharge, have theresult that the said is subjected to a considerable. outwardly directedpressure which radiates from the centre of explosion.` Thereby the sandor the soft ground is compressed and thus is rendered more impenetrablefor the v outflow of the oil.. l

This invention relates to an im roved method of and explosive members orthe blasting Vof blast-holes in hard, soft, sandy4 or moist rocks oround with ,the same lfavourable result. lccording tothe presentinvention, thick-walled ex losive members are used, whichin view o themechanical force of their splinters break up the rock and in soft groundform channels. These explosive members are units of cylindric shape andof standard size. The charge can be deter# mined and a projectile of anydesired length can be produced by suitablyv combinin a number of units011v the place of workmg.

ers litted with time fuses, electric fuses The initial ignition iscarried out by a percussion or time fuse ofknown construction, which isfitted to the projectile at the place of working. i

IExplosive members, provided with percussion fuses, are dropped fromoutside into the blast-hole, which previously has been filled withwater,'and,exp1ode when striking the floor. In the vcase ofexplosivememberslet down by a rope, the fuse can be vtimed or set beforethe insertion in the blast-hole or -it can be automatically disengagedwhen pulling up the rope. K

A suitable division ofthe proj ectile-casing `by notches or bytheinsertion of rings, inter'- mediate layers, vwashers and the like causesthe falling to pieces into a large number of small splinters which canbe readily destroyed bydrilling after the explosion. The

.effect of explosion is carried out preferably in a horizontal directionand the danger of damaging the pipes'is reduced, because the w'alls ofthe explosive member have taken up the greatest part lof the explosiveaction, thus according to the construction more than the ends of theprojectile. All parts of the explosive member consists of brittle butvnot too hard materials. x

Two modes of carrying out the present in vention are illustrated by wayof example on the accompanying sheet of drawings in which- Figs. 1 and 2show two constructions of the explosive member in longitudinal section.

Fig. 3 is a cross-sectional view of the memier, the section being takenon line A-A of In the construction shown in Fig. 1,- the thick-walledcasing lof the .explosive member consists of a brittle material and isprovided at bothends with an external screwthread 2 Iand with aninternal screw-thread 3. Theinner wall of the casing is provided withlcircular grooves or notches 4. Screw threaded caps 5, provided withholes 6`for the insertion of a Spanner, maybe screwed'into' the-.1

internal screw-threads 3 of the casing l.

The hollow compartment 7, remaining between the casing 1 and thel caps5, serves for the reception of the explosive charge, insulating discsvbeing provided to protect the charge against moisture.

Screw-threaded sleeves 11, cooperating with the external screw-threads 2of the casings 1, can be used for connecting a number of such explosivemembers of standard size, in order to form a unit of explosive members.In this case the screw caps 5 may be dispensed Wth. The individualexplosive members may be connected to form a unit also by means of abayonet joint. In place of a screw cap 5, a fuse 15 is screwed into orneend of the projectile consisting ,of a number of explosive members,While the other end thereof is shut by a screw cap 5. The external.screw-thread 2 at this end ofthe casing may be utilized for theattachment of a bracket, eye or-the like through which a rope is passedin order to let down the projectile into the blast-hole.

In the construction shown in Figs. 2 and 3, a large number of metalrings 17, provided with notches or grooves 1 8 at the inner Wall arearranged within the casing 1, furnishe with longitudinally extendinggrooves 16, in

order to increase the number of splinters as Well as the resistance ofthe casing.

The explosion with torpedos according to the present invention is alsoparticularly effective invery soft sandy grounds and in connection withblast-holes which for instance in view of repeatedunsuccessfulexplosions are x considerab y larger than corresponds to'the diameter ofthe explosive member. The' splinters produce a large number of longchannels through which the oil passes from a lar e number of strata intothe blast-hole.

Claim'- Y 1. Explosive member for blasting blastholes in soft,oil-bearing rocks, sand and the like, comprising a thick-w lled casingfor the explosive charge, and gr oves4 in the cas ing sub-dividing thesame into sections,

Where by the explosion the casing is torn into I individual piecesaccording to the grooves to orm channels 'n the "soft ground throughwhich oil ows i to the blast-hole.

2. Explosive. member for blasting blas'tholes in soft, oil-bearingrocks, sand and the like, comprising a thick-Walled casing for theexplosive charge, grooves in the casing, and rings arranged between the'explosive charge and the casing vvhichi'ncrease the resistance of thecasing and the'number of splinters.- In testimony whereof I lalix mysignature.

HANS GEORG ULRIK.

